Uncertain Allies
by sirensbane
Summary: Underestimating an enemy has deadly consequences. Even gods are not invulnerable. Set after the events of the first Avengers.
1. Chapter 1

"Goons, warehouse, circling the wagons," Tony sighed. "Must be Thursday."

"Indeed it is," Thor called back with a grin, smashing another series of opponents. "Though if you hurry, Friend Stark, I will save some for you!"

" _You'll_ save some for _me?_ " Tony exclaimed indignantly, and blasted two enemies with his repulsors. "Who's in the flying suit of armor shooting lasers from his hands?"

"No lightning," Steve said preemptively. "We're in a building, Thor."

"Very well," Thor said, though he did not sound pleased.

Tony whistled. "Better luck next time."

Thor's eyes narrowed, and he raised Mjolnir.

"Woah, woah, Big Guy," Tony backpedaled, "take it ea..."

Too late. The hammer flew...past Tony, missing him by nearly two feet to strike an enemy menacing Natasha. The demigod widened his eyes innocently as Mjolnir returned to his hand.

"Is something wrong, Stark?" he asked.

"Ha, ha," Tony grumbled, spinning to shoot at three goons who had opened fire at once. Thor just grinned.

"Thor!" Steve called. "Behind you!"

Tony spun in midair to see a man with a knife lunging at Thor's back. He couldn't easily strike at the guy with Thor's bulk in the way, but Thor's armor could reflect machine gun fire, let alone a simple knife. The demigod began to turn at Steve's warning, his hammer curving in an arc. Instead of impacting just above Thor's spine, the knife hit his shoulder…and sank through the armor as though through butter.

Thor roared in surprise and pain but completed the turn, ripping the knife from his attacker's grip. The man tried to stumble backward, but Thor sprang after him. There was a sickening crunch.

That crunch was too much for the rest of the thugs. Almost as one, they broke and ran. The Avengers let them go.

"Thor, you okay, buddy?" Tony demanded, landing beside him.

"Yes," Thor said, though his face looked a little pinched with pain. "It was not a fatal blow." He started to reach back for the blade and winced. "I had thought these ordinary mortal foes, but only an enchanted weapon could have pierced my armor."

"Stop that, you idiot," Natasha said. "You'll tear it open further."

They found a chair for Thor that wasn't too rickety, and he sat while Natasha examined the knife still sticking out of his back. He never removed the armor if there was still a chance for battle, but the links surrounding the injury spun aside. The rest of the team gathered around anxiously (except for Hawkeye, who kept an eye out for thugs returning).

"It looks like it went in cleanly," the Widow said after a moment. "But if we wait much longer to pull it out, you might just heal around it."

Thor nodded. "Pull it out."

It was dirty in the warehouse, but no one argued. Thor's immune system was nearly as impressive as his strength. Steve found a mostly clean cloth tucked away in a corner and brought it to Natasha. She gripped it in one hand and the dagger in the other.

"On three," she said.

Thor let out a deep breath and visibly forced himself to relax.

"One." The dagger came out with a pop. Blood welled up, but Natasha expertly covered it with the cloth and began to apply pressure. Thor's only reaction was a soft grunt of pain.

"Eiir has never waited either," he said. "I believe you would like her."

"Your family doctor?"

"The head of the palace healers." Thor barely seemed to notice the gaping hole in his back.

Natasha lifted the pad to check the injury beneath. "It looks like it's already stopped bleeding. Just don't do anything stupid like tear it open again."

Thor rotated carefully in his chair and smiled at her. "Thank you, Lady Natasha. This is not the first time you have treated wounds."

Clint snorted from the rafters. "Are you kidding? Tasha does all my injuries."

"And that's besides all the times she's done mine," Steve said.

"She makes me somewhat redundant," Bruce agreed, buttoning up the last button of the spare shirt Steve now carried with his gear.

"Nah," Tony said. "Widow's good, but she just doesn't do smash like you do."

"Thor does okay," Bruce said, looking at the last man Thor had killed. The rest of the team followed his gaze. It was actually a bit of a disturbing sight.

"I wish I had not acted so hastily. Perhaps he could have given us information about this group's allies, " Thor said. "Once more, I allowed anger to get the best of me." He got to his feet and winced. "So am I paid."

"Still, Avengers 20, attacking goons 0," Tony said airily. "We can figure out why they had enchanted weapons later. Shawarma sound good to anyone else?"

Clint groaned. "What is it with you and shawarma, Stark?"

"Hey, it's a delicious, culturally diverse meal," Tony defended himself. "Don't tell me you don't enjoy it, Birdbrain."

"Meat sounds good," Thor said. "I care not what variety."

"Let's have hamburgers this time," Bruce said. "I know this little place on 7th..."

Suddenly, Thor groaned. The team turned to look; the Asgardian's face had gone a lot paler beneath his beard.

"My friends," he managed before his knees buckled.

"Thor!"

Facedown on the floor, Thor did not respond.


	2. Chapter 2

Tony flew Thor back to the Tower, cradling the man as carefully as possible. No one wanted to wait for a Quinjet, and quite frankly, even the SHIELD agents didn't trust SHIELD not to take samples or run unnecessary tests on Thor while he was in no state to protest. Thor swam in and out of consciousness, but thankfully he didn't fight.

By the time the rest of the team arrived, Tony, Pepper, and Happy already had Thor in the med bay with JARVIS monitoring his life signs.

"Captain?" Thor asked when Steve entered, normal rumble more of a mumble. "What...what happened?"

"What do you remember?"

Thor closed his eyes. "I was...stabbed," he said at last. "Stark spoke, and I felt ill..."

"That's a pretty common reaction," Clint joked. Steve hushed him with a look.

"And then," said Thor. "Nothing."

"We think you were poisoned," Natasha said.

"Poisoned?" His voice was fainter, and he seemed to be struggling to stay awake.

"That knife that went into your shoulder," Steve said.

Thor lifted his hand vaguely. The injury had nearly sealed shut already, but the skin was redder than it should have been.

"Pouch," he slurred. "In my armor."

Then he was out again.

"Any idea what he's talking about?" Tony asked as Steve headed for Thor's armor, stacked neatly nearby. Thor hadn't been conscious enough to send the rest of it back to its usual extra-dimensional storage place, so Tony and the bots had taken it off manually.

"Not sure, but there's only one pouch here." Steve lifted a tiny grey bag that he'd discovered in an interior pocket. The team crowded around as he loosened the drawstring and opened it up.

"Rocks," Clint said.

They were. Most were brown, but one was a dull grey, and another was green with carvings on it.

"Any idea what we're supposed to do with them?" Bruce asked.

"No idea," Tony said. "Hey, JARVIS. Get Foster on the phone. Ask her if she knows anything about Thor's magic rocks."

Despite the seriousness of the situation, Clint sniggered.

Tony glared at him. "And tell her I'll be sending a Stark plane to pick her up."

* * *

"I'm not sure what the green and grey ones do," Jane Foster said, brushing a strand of hair out of her face and staring worriedly at them from the screen. "But I think the brown ones are healing stones. Thor described them to me once, and he said his people keep them around for serious injuries."

"Any idea how to activate one?" Steve asked.

"No," Foster said, her forehead creasing. "Usually, Thor's injuries just...How did this happen anyway? Your minions didn't explain very much when they hustled me aboard this plane."

Steve outlined the series of events for her, and at the end of it, Foster's face had grown even more worried. "Is he awake?"

They all glanced at the demigod unconscious on the bed. "Um, not right now," Bruce said. "But if we can figure out how these healing stones work, that would help a lot."

"Okay." Jane ran her fingers through her hair. It appeared to be a nervous habit. "Um...maybe there's a code or, I don't know, ignition sequence? I guess it could just be activated by the presence of magic, but I don't think all of Asgard's warriors can use magic, so it would be pretty silly to design a stone that would only heal some of them."

"Would have to be pretty simple," Clint said, "if you're supposed to use it when you're hurt. Blood loss does weird things to your head."

"Okay, so like a password," Steve said, staring at one of the brown stones. "Um...All-Father? Odin?"

The stone remained stubbornly normal.

"It wouldn't be anything you would use in casual conversation," Natasha put in. "Otherwise, it could activate when there's no injury."

They tried a number of words: heal, wound, blood, pain, cure, activate, and "work, you stupid stone..." Nothing happened.

"Maybe you just have to put it on the injury," Bruce said at last.

Steve touched the stone to the redness, as there wasn't really a cut anymore. Nothing happened.

"Here," Bruce said. "I've been meaning to do this anyway. Maybe let some of the poison out." Before any of them could react, he took a knife out of the medical sterilizer and created a shallow cut across Thor's shoulder. Blood came out, of course, but so did a foul-smelling pus.

"Quick, Cap," Bruce said, holding one hand over his nose and mouth. Sure enough, the injury started healing shut almost immediately.

Quickly, Steve touched the stone to the injury. Nothing happened, except that the stone got a little stained.

"Any more ideas?"

Silence.

Then Tony snapped his fingers. "Hey, this thing's Asgardian, right? So all we have to do is think like Asgardians." He took the stone from Steve and tossed it towards Bruce. The scientist fumbled, but managed to catch it on the tips of his fingers. "Smash."

They all considered that.

"You really think it could be that simple?" Steve asked.

Tony shrugged. "Why not?"

"That's a pretty big generalization of Thor's people, isn't it?" Bruce said.

"Hey, I can apologize to Blondie later if he gets offended."

Clint shrugged. "Hell, why not? It's not like it's any crazier than the rest of the stuff we've had to deal with."

The resulting silence was agreement.

"You'd better do the actual smashing, Cap," Bruce said, gingerly handing the stone to Steve. "I mean, the Big Guy could do it, but he'd probably smash the rest of the med lab too."

Steve closed his fingers around the little stone. "Are you sure about this, Tony?"

Tony made an impatient noise. "You have a better idea?"

Steve squeezed. The stone crumbled with surprising ease, which seemed to lend credence to Tony's theory. Steve's hand was left full of dust.

"Make the cut again, Bruce," Clint said, standing up to see better.

Bruce did so, and when the blood welled up, Steve tipped a little of the dust onto the injury. It glowed bright gold, and the bleeding slowed immediately.

Tony held his hands out for acknowledgement. "I'm a genius."

"Well, it's a step in the right direction," Bruce admitted. "But will it deal with infection?"

"First, get more of it into the bloodstream," Natasha said. "Then wait and see."

"Put gloves on before you stick your hands in there, Cap," Clint said, making a face.

 _Probably a good idea with poison_ , Steve thought, and followed his teammate's advice.

Bruce cut the injury open wider. Pus oozed out again. Ignoring his revulsion, Steve worked his handful of dust deep into the cut. The gold glow came again, much brighter, and they shielded their eyes. Steve felt a sucking sensation and had barely withdrawn his fingers before the cut healed shut without a trace.

"Now," Bruce said. "We wait."

* * *

Jane arrived shortly afterwards, and immediately went up to see Thor. The demigod was awake, and he smiled when he saw her. Holding his hand tightly, Jane explained about the healing stones. He'd smiled again, this time with obvious relief, and fell asleep again.

Steve wasn't as confident. The redness didn't fade. If anything, it spread. Around dinner time, Bruce cut the injury open again. It took five minutes before pressing on the skin stopped releasing pus. Tony turned green. After he had cleaned it out carefully, Bruce suggested another healing stone. Other then the by-now familiar gold glow, nothing happened.

Worse, Thor kept slipping in and out of wakefulness. Sweat stained his forehead, and he began to mumble and moan.

"Maybe you shouldn't do that," Bruce told Jane finally. "Hold his hand."

"What are you talking about?" Jane demanded. "I'm not going to leave him all alone."

"Of course not," Bruce said gently. "But what if he starts hallucinating?"

As Bruce's point sank in, Tony winced. He had witnessed firsthand how tightly Thor could squeeze, and that had been the specially reinforced metal of the Iron Man suit. Jane's fingers would be completely crushed. Awkwardly, he laid a hand on Jane's shoulder.

"Hey, maybe we should listen to him, Jane," he said. "He's a doc and all." Jane looked up at him, an agonized expression in her eyes. It wrenched at Tony's heart. He tried to keep his tone light. "And hey, if Romeo needs comfort, we'll put you in an Iron Man suit."

Jane gave him a watery smile. "Alright." Then she fixed Bruce a determined gaze. "But I'm staying with him in case... _until_ he wakes up."

* * *

Jane and Bruce stayed by Thor, Bruce to see if he could do anything more, and Jane to soothe Thor as he tossed and turned. Tony locked himself up in the lab, examining the poisoned knife again and again and trying to synthesize an antidote. Clint and Natasha went to vent their frustrations and fears on the range.

That just left Steve. For a moment, he thought about following the assassins, but he had a vague notion that they wanted to be alone. After wandering the Tower aimlessly for nearly half-an-hour, he finally went down to the garage and retrieved his motorcycle. The roar of the engine was comforting.

Looking back, it was probably a miracle that he wasn't struck and killed. He roamed, escaping the city as soon as possible to ride at daredevil speeds along the freeways. He couldn't bring himself to go that far, however; what if Thor's condition changed? But neither could he bring himself to return to the Tower.

Eventually, he found himself outside the old-fashioned gym that he had used before moving to the Tower. After only a moment of indecision, Steve parked the bike and went inside. He collected a punching bag from the rack, nodded to the guy at the desk — all the staff here knew him — and went to hang it up.

Left. Right. Left. Right. Left. Harder and harder until his unwrapped knuckles began to hurt. He paused just long enough to wrap them and then returned to the bag. Right. Left. Right. Left.

 _You can't afford to fall apart,_ an inner voice reminded him. _Get it together._

Right. Left. Right. Pause to replace the bag as it came off the hook with a resounding thud. Luckily, there wasn't anyone to see except the owner, and he was probably used to this kind of thing by now.

Left. Right. Left. Right. Left. Right. Left. Right.

"That bag insult your mother, Son?"

Steve stopped in the act of lifting another punching bag onto the hook and turned to see the owner standing at a safe distance behind him. Steve ran a hand through his hair and was surprised to see that it was sweat-soaked.

"Sorry," he said sheepishly. "I guess I'm a little stressed. I'll pay for the replacements..."

The man shrugged. "That's not what I'm worried about." At Steve's blank look, he added, "Kid, you've caved in two punching bags in the last fifteen minutes, and there's a look on your face like someone just shot your dog."

"Sorry," Steve said again. He didn't know what else to say, honestly. _My friend the weather-controlling alien prince was stabbed in the back, and I'm worried he might die because I didn't warn him in time about the guy with the poisoned blade?_

The owner studied him. "Something I can help with?"

"No. It's just...I made a mistake, and it hurt someone I care about."

"Have you done everything you can to fix it?"

 _What else, realistically, can I do?_

"I guess," Steve admitted.

"Just keep that in mind."

At that very moment, Steve's cell phone buzzed from where he'd left it on the bench. The caller ID said _Tony Stark_. With an apologetic nod at the owner, Steve snatched it up. "Hello?"

"Cap," Tony said. He sounded tense. "Thor's going into convulsions. Where the hell are you?"

Desperately, Steve turned to the owner. "Can you..."

"I'll get it cleaned up," the owner said. "Go see your friend."

Steve was gone almost before he'd finished his sentence.

* * *

"We don't have a choice," Barton said grimly. "We have to call in SHIELD."

Thor lay still and unconscious on the bed. The convulsions had stopped for now; Bruce had pumped in enough medicine to kill an elephant, but Steve had the horrible impression that they would only provide a temporary relief.

"There's another option," Tony argued. "Asgard."

"And what's their reaction going to be when they find out that someone from Midgard was responsible for injuring the heir to the throne?" Natasha asked.

"Worse than their reaction if Thor dies?" Tony shot back, then immediately paled. The rest of the team did the same, staring as one at the figure on the bed. The injury had closed up again, but the circle of red was much larger, and they all hoped they were imagining the tiny nub of black in the center of it.

"We call Asgard," Steve said firmly into the silence. "Even if they're angry and keep Thor from coming back again, that's better than risking our teammate's life."

No one disagreed.

"Any idea how we get hold of them?" Clint asked.

"Just one," Steve said. He tilted his head upward. "Heimdall!"

"You think that'll work?"

Minutes ticked by. Nothing.

"Heimdall!" Steve tried again. "Thor's been poisoned. He needs a doctor!"

"Sir," JARVIS said. "I am detecting some unusual energy readings in the air above Stark Tower. They are consistent with the readings collected at Puente Antigua."

"The Bifrost," Jane said.

"Finally," Tony said, striding towards the door of the med bay. "C'mon boys and girls. Let's form a welcoming committee."


End file.
